even more byte utils optimizations

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/utils/bytes.rs

@@ -3,27 +3,28 @@ use crate::Result;
 #[inline]
 #[must_use]
 pub fn increment(old: Option<&[u8]>) -> [u8; 8] {
-	old.map(TryInto::try_into)
-		.map_or(0_u64, |val| val.map_or(0_u64, u64::from_be_bytes))
+	old.map_or(0_u64, u64_from_bytes_or_zero)
 		.wrapping_add(1)
 		.to_be_bytes()
 }
 
-/// Parses the big-endian bytes into an u64.
-#[inline]
-pub fn u64_from_bytes(bytes: &[u8]) -> Result<u64> {
-	let array: [u8; 8] = bytes.try_into()?;
-	Ok(u64_from_u8x8(array))
-}
-
-/// Parses the 8 big-endian bytes into an u64.
+/// Parses 8 big-endian bytes into an u64; panic on invalid argument
 #[inline]
 #[must_use]
-pub fn u64_from_u8(bytes: &[u8]) -> u64 {
-	let bytes: &[u8; 8] = bytes.try_into().expect("must slice at least 8 bytes");
-	u64_from_u8x8(*bytes)
-}
+pub fn u64_from_u8(bytes: &[u8]) -> u64 { u64_from_bytes(bytes).expect("must slice at least 8 bytes") }
+
+/// Parses the big-endian bytes into an u64.
+#[inline]
+#[must_use]
+pub fn u64_from_bytes_or_zero(bytes: &[u8]) -> u64 { u64_from_bytes(bytes).unwrap_or(0) }
+
+/// Parses the big-endian bytes into an u64.
+#[inline]
+pub fn u64_from_bytes(bytes: &[u8]) -> Result<u64> { Ok(u64_from_u8x8(*u8x8_from_bytes(bytes)?)) }
 
 #[inline]
 #[must_use]
 pub fn u64_from_u8x8(bytes: [u8; 8]) -> u64 { u64::from_be_bytes(bytes) }
+
+#[inline]
+pub fn u8x8_from_bytes(bytes: &[u8]) -> Result<&[u8; 8]> { Ok(bytes.try_into()?) }